Characteristics of CO2 in unsaturated zone (～90 m) of loess tableland, Northwest China

• 作 者: Chao Song Guilin Han Yingchun Shi Congqiang Liu Pan Wang
• 机 构: School of Water Resources and Environment, China University of Geosciences (Beijing),The Institute o
• 出 处: Acta Geochimica
• 发表日期: 2017年03期
• 关键词: Unsaturated zone Soil CO2 Carbon stock in deep loess Quantitative paleoclimate r

In order to observe CO_2 characteristics in the unsaturated zone of loess tableland and further understand the carbon cycle,a series of tubes for gas monitoring and sampling were installed in an approximately 90-m deep Qiushe loess section of Lingtai County,Northwestern China.The results show that the concentration of CO_2 was higher in loess than in the atmosphere,reaching a maximum of 6970 lmol·mol~(-1).CO_2 concentrations in loess were higher in summer than in winter.The CO_2 in loess was related to organic carbon decomposed by microbes,and to the CaCO_3–H_2O–CO_2 system in the interface between the saturated and unsaturated zones.

In order to observe CO_2 characteristics in the unsaturated zone of loess tableland and further understand the carbon cycle, a series of tubes for gas monitoring and sampling were installed in an approximately 90-m deep Qiushe loess section of Lingtai County, Northwestern China.The results show that the concentration of CO_2 was higher in loess than in the atmosphere, reaching a maximum of 6970 lmol · mol ~ (-1). CO_2 concentrations in loess were higher in summer than in winter. CO_2 in loess was related to organic carbon decomposed by microbes, and to the CaCO 3 -H 2 O-CO 2 system in the interface between the saturated and unsaturated zones.